This invention provides a surgical device allowing the percutaneous connection of two soft tissue areas that are ordinarily separate. This device is particularly intended for reconstruction of heart valves, especially the mitral valve, and for the treatment of any malformation of a heart septum.
In a condition known as mitral insufficiency, the mitral valve does not completely shut, and does not prevent the back-flow of blood to the left atrium from the left ventricle. Surgical repair is then necessary. In a current procedure, a sternotomy is performed. The patient is then placed under extra-corporal blood circulation while the heart is stopped, and the heart chambers are opened to gain access to the mitral valve, usually through the left atrium. Once the mitral valve is accessed, repair procedures include annuloplasty and, more recently, suturing of the free edge of the anterior leaflet to the free edge of the back leaflet where the mitral insufficiency occurs.
These procedures are complicated and require general anesthesia, sternotomy and extra-corporal blood circulation. They also require high doses of anti-coagulant therapy adding to the operative risk of a myocardial infarction and hemorrhage.
The methods of the present invention are performed percutaneously, diminishing considerably these risks. A surgical device allows the connection of two zones of soft tissue that are usually separate. In a particular embodiment, a connection is formed between a free edge area of an anterior mitral leaflet and a free edge area of a back mitral leaflet. Suitable surgical devices for performing tissue connection are described for example in EP 558 031 and WO 94/18893, and may comprise:
(a) a tube which may be inserted percutaneously until its distal extremity reaches the area around the tissues to be connected; and
(b) two elongated elements inside that tube, each of which comprises a distal extremity having a device that grasps one of the two tissues to be connected;
(c) wherein the distal extremities of these elongated elements may be opened and closed in order to permit introduction into the desired area, allow the procedure.
Particular devices according to the present invention may further comprise:
(a) a grasping element, optionally having two parts for capturing each of the tissues to be connected, wherein the grasping or hooking element effects the connection of the two zones of tissue when brought close thereto by shifting of the portions of distal extremities to a position where they meet;
(b) a rod connected to each of the grasping or hooking elements and operated from the proximal end of the tube in order to axially shift the elongated element, wherein the rod can be separated from the grasping or hooking element upon pulling beyond a given threshold; and
(c) a wedge inside the tube, allowing the axial immobilization of each grasping or hooking element while pulling on them.
The rod positions the insertion of the hooking element up to the level of the tissue edges to be connected. The rod also engages the hooking element against the wedge in order to open the two hooking parts.
According to the present invention, the device may be used to remotely grasp through a percutaneous passage, to draw together, and to connect the two zones of tissue by a simple external manipulation.
Preferably, the tube, the elongated elements, and the rod are flexible enough to be inserted percutaneously and through a patient""s vasculature for the treatment of the leaflets of a cardiac valve, in particular the mitral valve. Each of the elongated elements is made out of an elastically flexible material, and one of these elongated elements diverges from the longitudinal axis of the other. The two elongated elements can move axially in relation to the tube between (a) a retracted position within the tube where the ends of the elongated elements are flexibly bent and closed together, and (b) a position where the ends of the elongated elements spring open and diverge from each other in a way that permits those ends to capture the soft tissues in order to grasp them.
The elongated elements may be deployed to allow their distal extremities to grasp the tissue areas or may be retracted in order to make the insertion, shifting or removal of the apparatus easier. Each elongated element may comprise a rod made of elastic material, with a curved distal extremity and/or a harpoon shape, and a sheath able to slide axially in a forward position to cover the distal extremity and slide back to uncover it.
According to a variation, each elongated element can be composed of a tube linked to a system that contracts its internal volume in order to grasp the corresponding tissue area, and expands to release the tissue with no lesion. In this case, the wide-mouthed shape of the elongated element""s distal extremity will insure a large enough grasping surface.
Preferably, the device includes two hooking elements. One is operated on the distal side of the tissues, and the other, to be operated on the proximal side of the tissues, is situated between the first hooking element and the wedge element. This way the two hooking elements can be operated on both sides of the tissues and can be pressed together for a perfect attachment of those tissues.